Super low idle

[ztmj]

I know it may be a common problem but i think it may be different in my case & here is why.
About 4 weeks ago my timing belt busted. I drive a 98' eclipse spyder gst 2G 4g63 by the way. I decided to replace the head, the one that was put on was a rebuilt 2G head with 1G cams. I also replaced the timing kit & water pump.
By the 7th i had my car back, i noticed the problem the next day. I talked with the mechanic & was told to adjust the idler. Up to now thats barly helping, before i put it in gear it idles really low, & when I put it in drive/reverse it idles so low that it has actually died on me a few times. I have the idler adjusted all the way up & it barly idles @ 1000rpm & still wants to shut off. This morning though, my check engine light came on & it kept a steady idle, still pretty low @ around 1000rpm with the idler all the way up as said before. What could be the problem(s) & how can they be fixed?

 

[92AWDHX40]

Terry's Talon Troubleshooting Tips #3 - Fast Idle (aka. Idle Surge)

this may not be your issue but it is regarding idle, could be the isc, a boost leak, tps issues wiring, many things.

 

[LiquidX]

Double check the mechanical timing to be sure it's correct especially since you did not do the swap.

Are you using a 1g CAS or no? Stock RPM is 750 which is it should be set to unless you are using ecmlink or an equivalent to internally set your idle.

The computer wants 750 rpm and messing with the Biss will throw the IAC out of adjustment as it is trying to get a 750 rpm idle.


What is the CEL for?

 

[ztmj]

What is the isc? i've never heard the abbreviation

I dont know why the CEL came on, like i said it happend this morning

 

[LiquidX]

ISC/IAC, same thing. It's the idle speed controller on the throttle body which is on the lower half.

 

[ztmj]

I honestly don't know what CAS was used, what if it is a 2G?

 

[bradselph]

If its a 2g cas the intake cam would have to be drilled and tapped for the cas to work on the 1g cam.

 

[LiquidX]

I honestly don't know what CAS was used, what if it is a 2G?

Do you have a round sensor off of your intake cam on the passenger side that looks like this:

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or

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You need to get the car to an Autozone or similar where they will read the check engine light by hooking up a diagnostic tool to the OBDII port under the steering wheel towards the center console. They will give you at least 1 code and a description. Get it read and give us the code/s so we can better diagnose and troubleshoot your issue.

It may still be a very good idea to verify mechanical timing and if you have the 1g CAS as shown above, to get a timing light and verify that your ignition timing is at 5* BTDC as well.

 

[Smeed78]

If its a 2g cas the intake cam would have to be drilled and tapped for the cas to work on the 1g cam.

I thought that it only has to be drilled and tapped if its going to remain a 2G CAS? When I got my DKS 272/272 my CAS was converted to a 1G since the cam wasn't drilled and tapped. The mechanic said the 1G is better than the 2G anyways.

 

[ztmj]

well its the one on top, my mechanic got the CEL issue fixed & fixed the idleing problem, well it seemed that he did. the idleing is starting to drop again. im thinking it might be the ECU i dont think it was calibrated for thr 1G cams, it being a 2G. I don't know though.
when i drive it works great, it's when i come to a stop the idle starts to drop if I sit for too long. it idles like its running out of gas. Well thats the only way I can discribe it anyway.

 

[LiquidX]

The cam won't make a difference with your idle issue.

 

[ztmj]

what about the throttle? i adjusted it because it seemed that the engine wasn't getting enough gas. it was working great after that, but after a couple weeks it started to want to shut off again when i have the a/c on & shift into gear more so in reverse than in drive. It isn't as bad as before with the adjustment i made to the throttle, so it doesn't sound like it's not getting enough gas, but the RPMs drop so low that sometimes it shuts off in reverse unless i press the accelarator a little more. Also sometimes when i put it in park or neutral the RPMs go up & down several times between just over 2000 & just over 1000, these are the RPMs with the a/c on so im guessing that they are probably higher with it off. i took a look & right now it idles at 1600 RPM, with a/c 1100 RPM. the mechanic say the timing is on point & the vacume hoses are in the right locations. What could be the cause?

what about the ECU?